1. The Field of the Invention
The present invention relates to a self lubricating chain which may be used as a roller chain, a bush chain, a bushless roller chain or a chain where the roller is fitted directly onto a roller pin without using a bush. More particularly, the present invention relates to a self-lubricating chain which may be used as a bucket chain for loading iron core, coal, and the like, as a chain for conveying heavy loads, such as automobiles, and the like, or as a flow conveyor chain for conveying granules.
2. The Relevant Technology
In one self-lubricating chain currently known in the art, an outer link and inner link are connected together in a large number according to the specific requirements of the chain. The outer link includes at least two outer link plates which are connected to the inner links using front and rear connecting pin holes into which a connecting pin is fitted. The inner link includes at least two inner link plates which are connected together using front and rear bushes, which may be fit-secured bushes or loosely fitted bushes. In this chain, a lubricating hole is formed in the center of the connecting pin in the longitudinal direction. A hollow portion is formed on one side of the connecting pin and is used for attaching a lubricating oil supply device to the hollow portion so that lubricating oil is supplied from the lubricating hole to the outer circumferential of the connecting pin.
An example of one such connecting pin 510 currently known in the art is shown in FIG. 7. The connecting pin 510 includes a lubricating hole 511 formed at the substantially central portion in a longitudinal direction of the connecting pin which opens at an outer circumferential surface 510a, so that a lubricating oil can be supplied to the outer circumferential surface 510a of a connecting pin through the lubricating hole 511.
The connecting pin 510 also includes a hollow portion 512, which extends from one side of the connecting pin 510 to an end portion 513 which is located at the center of the connecting pin in the longitudinal direction. The bottom portion 513 includes a concave fitting portion 514 having a lubricating oil inflow port 514a which communicates with the lubricating hole 511.
A lubricating oil supply device 520 is detachably mounted to the hollow portion 512. The oil supply device 520 has a length substantially equal to the length of the hollow portion 512. At a front end of the lubricating oil supply device 520 is formed a protruding portion 521 having a lubricating oil outflow port 521a. When the lubricating oil supply device 520 is attached to the hollow portion 512, the protruding portion 521 is screwed in the concave fitting portion 514 so as to be brought into close contact therewith, and the lubricating oil outflow port 521a of the protruding portion 521 and the lubricating oil inflow port 514a of the concave fitting portion 514 are connected to each other so that a lubricating oil reservoir 522 and the lubricating hole 511 communicate with each other.
An outflow mechanism, which allows a lubricating oil to gradually flow out of the lubricating oil outflow port 521a is formed at the substantially central portion in a longitudinal direction of the connecting pin, and a lubricating oil within lubricating oil reservoir 522 is supplied to the outer circumferential surface 510a of the connecting pin. This continues until the lubricating oil within the lubricating oil reservoir 522 is depleted, at which time the supply of the lubricating oil is performed by exchanging the lubricating oil supply device 520.
An example of one such chain currently known in the art is described in Japanese Patent Publication No. 2007-246234.
One problem with this configuration, however, is that the lubricating oil supply device 520 is screwed into the hollow portion 512. Thus, at the time of attaching or detaching of the lubricating oil supply device 520, it is necessary to turn the entire lubricating oil supply device 520. Unfortunately, this process is time consuming, and it is necessary to spend a large amount of time to replace the oil supply device 520.
Further, since the lubricating oil supply device 520 is loosely fitted into the hollow portion 512, a space is formed between the lubricating oil supply device 520 and the hollow portion 512, meaning that foreign matter can enter from the outside. Additionally, as the self-lubricating chain is driven, vibrations form in the space, generating noise or loosening the screw between the protruding portion 521 and the concave fitting portion 514. In some instances, these problems can lead to leaks and the deterioration of the chain.
Also, because one end of the lubricating oil supply device 520 is exposed, it is possible that the oil supply device 520 may become damaged or broken as articles are conveyed by the chain.
Accordingly, there is a need for a self-lubricating chain which solves the above-mentioned prior art problems by allowing the quick and easy replacement of the lubricating oil supply device, wherein the chain and oil supply device prevent the entry of foreign matter, reduce the vibration of the lubricating oil supply device due, reduce noise, and prevent leakage and deterioration of the chain.
The subject matter claimed herein is not limited to embodiments that solve any disadvantages or that operate only in environments such as those described above. Rather, this background is only provided to illustrate one exemplary technology area where some embodiments described herein may be practiced